Method for treating fecal incontinence

ABSTRACT

A method for treating fecal incontinence in a body of a mammal having a rectum formed by a rectal wall extending to an anus wherein the rectal wall includes a sphincter muscle surrounding the anus. At least one nonaqueous solution is introduced into the rectal wall in the vicinity of the anus. A nonbiodegradable solid is formed in the rectal wall from the at least one nonaqueous solution.

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 09/286,245 filed Apr. 5, 1999, which is acontinuation-in-part of U.S. patent application Ser. No. 09/232,056filed Jan. 15, 1999 and claims priority to U.S. provisional patentapplication Serial No. 60/111,884 filed Dec. 11, 1998, the entirecontents of each of which are incorporated herein by this reference.

[0002] This invention pertains to the treatment of the gastrointestinaltract and, more particularly, to the treatment of fecal incontinence.

[0003] Fecal incontinence, which is most common in the elderly, is theloss of voluntary control to retain stool in the rectum. In most cases,fecal incontinence is the result of an impaired involuntary internalanal sphincter. The internal sphincter may be incompetent due to laxityor discontinuity. Discontinuity, or disruption of the internal analsphincter, can be caused by a number of different muscle injuries.

[0004] In most patients, fecal incontinence is initially treated withconservative measures, such as biofeedback training or alteration of thestool consistency. Biofeedback is successful in approximately two-thirdsof patients who retain some degree of rectal sensation and functioningof the external anal sphincter. However, multiple sessions are oftennecessary, and patients need to be highly motivated. Electronic homebiofeedback systems are available and may be helpful as adjuvanttherapy.

[0005] Several surgical approaches to fecal incontinence have beentried, with varying success, when conservative management has failed.These treatments include sphincter repair, gracilis or gluteus muscletransposition to reconstruct an artificial sphincter and colostomy. Theapproach that is used depends on the cause of the incontinence and theexpertise of the surgeon. For example, biodegradable compounds have beeninjected or introduced into the anal sphincter to bulk the rectal wall.Unfortunately, such biodegradable compounds are resorbed by the body andthus become ineffective over time.

[0006] In general, it is an object of the present invention to provide aminimally invasive method and apparatus for treating fecal incontinence.

[0007] Another object of the invention is to provide a method of theabove character for treating fecal incontinence in which one or moreimplants are formed in the rectal wall.

[0008] Another object of the invention is to provide a method of theabove character for treating fecal incontinence in which one or moreimplants are formed in the rectal wall in the vicinity of the analsphincter.

[0009] Another object of the invention is to provide a method of theabove character in which one or more implants of a nonbiodegradablematerial are formed in the anal sphincter for reducing thedistensibility of the anal sphincter.

[0010] Additional objects and features of the invention will appear fromthe following description from which the preferred embodiments are setforth in detail in conjunction with the accompanying drawings.

[0011]FIG. 1 is a sectional view of a portion of the human body in whicha portion of the anal sphincter is being treated by a method of thepresent invention.

[0012]FIG. 2 is a cross-sectional view of a portion of the analsphincter taken along the line 2-2 of FIG. 1.

[0013]FIG. 3 is a sectional view of a portion of the human body similarto FIG. 1 in which a portion of the anal sphincter is being treated byanother method of the present invention.

[0014]FIG. 4 is a sectional view of a portion of the human body similarto FIG. 1 in which a portion of the anal sphincter is being treated by afurther method of the present invention.

[0015]FIG. 5 is a sectional view of a portion of the human body similarto FIG. 1 in which a portion of the anal sphincter is being treated byyet another method of the present invention.

[0016]FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG.5.

[0017]FIG. 7 is a perspective view of an apparatus for use in the methodfor treating the anal sphincter of the present invention.

[0018] In general, a method for treating fecal incontinence in the bodyof a mammal having a rectum formed by a rectal wall extending to an anuswherein the rectal wall includes a sphincter muscle surrounding the anusis provided. At least one nonaqueous solution is introduced into therectal wall in the vicinity of the anus. A nonbiodegradable solid isformed in the rectal wall from the nonaqueous solution.

[0019] As shown in FIG. 1, the gastrointestinal tract includes therectum 21 and opens to the outside of body 22 at the anus 23. The rectum21 is formed by a rectal wall 24 substantially centered on a centerline25 of the rectum (see FIG. 3). The inner layer of the rectal wall 24 ismucosal layer 26, below which is submucosal layer 27. A layer of muscleextends around rectum 21 and also forms part of rectal wall 24. Suchmuscle layer comprises circular muscle layer 28 extending beneathsubmucosal layer 27 and longitudinal muscle layer 29 extending beneathcircular muscle layer 28. Body 22 further includes the anal sphincter 31having the sphincter ani internus 32 and the sphincter ani externus 33.Sphincter ani internus 32, an involuntary sphincter, forms the terminusof circular muscle layer 28 at anus 23. Sphincter ani externus 33, avoluntary sphincter, comprises a deep external sphincter 34, thesuperficial external sphincter 36 and the subcutaneous externalsphincter 37. For purposes of this application, the transition betweencircular muscle 28 and internal sphincter 32 comprises the transitionbetween rectum 21 and anus 23, also known as the anorectal border 38.Also for purposes of this application, rectal wall 24 and thus the wallof the gastrointestinal tract of body 22 includes both sphincter aniinternus 32 and sphincter ani externus 33 and thus, the wall of anus 23.Between external and internal sphincters 33 and 32 there exists thepotential space known as the intersphincteric space 39.

[0020] In the method for treating fecal incontinence of the presentinvention, an implantable material such as an implant-forming materialor solution is introduced into rectal wall 24 in the vicinity of analsphincter 31 by any suitable means to augment, bulk or otherwisedecrease the distensibility of the anal sphincter 31. The method of thepresent invention can be performed with any of the apparatus disclosedin U.S. patent application Ser. No. 09/286,245 filed Apr. 5,1999 andU.S. patent application Ser. No. 09/232,056 filed Jan. 15, 1999. Onepreferred apparatus for introducing the solution into rectal wall 24includes a conventional syringe 41 having a barrel 42 filled with thesolution. A conventional elongate needle 43 is connected to syringe 41for delivering the solution from barrel 42 into rectal wall 24. Tubularneedle 43 can be of a conventional type and, as such, provided with asingle opening at the distal end thereof. Alternatively, needle 43 canbe similar to any of the needles described in U.S. patent applicationSer. No. 09/232,056 filed Apr. 5, 1999. Syringe 41 is part of the supplyassembly of the apparatus of the invention for depositing one or moreimplants in the rectal area of the patient, and more particularly is afirst reservoir containing the implant-forming material. Preferably, thesupply assembly further includes a second reservoir containing asolvent, preferably a biocompatible solvent such as dimethyl sulfoxide(DMSO), and a third reservoir containing a suitable aqueous orphysiologic solution such as saline.

[0021] Although any suitable implant-forming material can be used withthe method and/or apparatus of the present invention, one such materialis at least one solution which when introduced into the body forms anonbiodegradable solid. As used herein, a solid means any substance thatdoes not flow perceptibly under moderate stress, has a definite capacityfor resisting forces which tend to deform it (such as compression,tension and strain) and under ordinary conditions retains a definitesize and shape; such a solid includes, without limitation, spongy and/orporous substances. One such embodiment of the at least one solution isfirst and second solutions which when combined in the body form thenonbiodegradable solid. Another such embodiment is a nonaqueous solutionwhich can be introduced into the body as a liquid and from which a solidthereafter precipitates. A preferred embodiment of such a nonaqueous orimplant-forming solution is a solution of a biocompatible polymer and abiocompatible solvent which can optionally include a contrast agent forfacilitating visualization of the solution in the body.

[0022] In one embodiment, an implant-forming solution is used that has acomposition comprising from about 2.5 to about 8.0 weight percent of abiocompatible polymer, from about 52 to about 87.5 weight percent of abiocompatible solvent and optionally from about 10 to about 40 weightpercent of a biocompatible contrast agent having a preferred averageparticle size of about 10 μm or less. It should be appreciated that anypercents stated herein which include a contrast agent would beproportionally adjusted when the contrast agent is not utilized. Anycontrast agent is preferably a water insoluble biocompatible contrastagent. The weight percent of the polymer, contrast agent andbiocompatible solvent is based on the total weight of the completecomposition. In a preferred embodiment, the water insoluble,biocompatible contrast agent is selected from the group consisting ofbarium sulfate, tantalum powder and tantalum oxide. In still a furtherpreferred embodiment, the biocompatible solvent is dimethylsulfoxide(DMSO), ethanol, ethyl lactate or acetone.

[0023] The term “biocompatible polymer” refers to polymers which, in theamounts employed, are non-toxic, chemically inert, and substantiallynon-immunogenic when used internally in the patient and which aresubstantially insoluble in physiologic liquids. Suitable biocompatiblepolymers include, byway of example, cellulose acetates (includingcellulose diacetate), ethylene vinyl alcohol copolymers, hydrogels(e.g., acrylics), poly(C₁-C₆) acrylates, acrylate copolymers, polyalkylalkacrylates wherein the alkyl and alk groups independently contain oneto six carbon atoms, polyacrylonitrile, polyvinylacetate, celluloseacetate butyrate, nitrocellulose, copolymers of urethane/carbonate,copolymers of styrene/maleic acid, and mixtures thereof. Copolymers ofurethane/carbonate include polycarbonates that are diol terminated whichare then reacted with a diisocyanate such as methylene bisphenyldiisocyanate to provide for the urethane/carbonate copolymers. Likewise,copolymers of styrene/maleic acid refer to copolymers having a ratio ofstyrene to maleic acid of from about 7:3 to about 3:7. Preferably, thebiocompatible polymer is also non-inflammatory when employed in situ.The particular biocompatible polymer employed is not critical and isselected relative to the viscosity of the resulting polymer solution,the solubility of the biocompatible polymer in the biocompatiblesolvent, and the like. Such factors are well within the skill of theart.

[0024] The polymers of polyacrylonitrile, polyvinylacetate, poly(C₁-C₆)acrylates, acrylate copolymers, polyalkyl alkacrylates wherein the alkyland alk groups independently contain one to six carbon atoms, celluloseacetate butyrate, nitrocellulose, copolymers of urethane/carbonate,copolymers of styrene/maleic acid and mixtures thereof typically willhave a molecular weight of at least about 50,000 and more preferablyfrom about 75,000 to about 300,000.

[0025] Preferred biocompatible polymers include cellulose diacetate andethylene vinyl alcohol copolymer. In one embodiment, the cellulosediacetate has an acetyl content of from about 31 to about 40 weightpercent. Cellulose diacetate polymers are either commercially availableor can be prepared by art recognized procedures. In a preferredembodiment, the number average molecular weight, as determined by gelpermeation chromatography, of the cellulose diacetate composition isfrom about 25,000 to about 100,000 more preferably from about 50,000 toabout 75,000 and still more preferably from about 58,000 to 64,000. Theweight average molecular weight of the cellulose diacetate composition,as determined by gel permeation chromatography, is preferably from about50,000 to 200,000 and more preferably from about 100,000 to about180,000. As is apparent to one skilled in the art, with all otherfactors being equal, cellulose diacetate polymers having a lowermolecular weight will impart a lower viscosity to the composition ascompared to higher molecular weight polymers. Accordingly, adjustment ofthe viscosity of the composition can be readily achieved by mereadjustment of the molecular weight of the polymer composition.

[0026] Ethylene vinyl alcohol copolymers comprise residues of bothethylene and vinyl alcohol monomers. Small amounts (e.g., less than 5mole percent) of additional monomers can be included in the polymerstructure or grafted thereon provided such additional monomers do notalter the implanting properties of the composition. Such additionalmonomers include, by way of example only, maleic anhydride, styrene,propylene, acrylic acid, vinyl acetate and the like.

[0027] Ethylene vinyl alcohol copolymers are either commerciallyavailable or can be prepared by art recognized procedures. Preferably,the ethylene vinyl alcohol copolymer composition is selected such that asolution of 8 weight-volume percent of the ethylene vinyl alcoholcopolymer in DMSO has a viscosity equal to or less than 60 centipoise at2020 C. and more preferably 40 centipoise or less at 20° C. As isapparent to one skilled in the art, with all other factors being equal,copolymers having a lower molecular weight will impart a lower viscosityto the composition as compared to higher molecular weight copolymers.Accordingly, adjustment of the viscosity of the composition as necessaryfor catheter delivery can be readily achieved by mere adjustment of themolecular weight of the copolymer composition.

[0028] As is also apparent, the ratio of ethylene to vinyl alcohol inthe copolymer affects the overall hydrophobicity/hydrophilicity of thecomposition which, in turn, affects the relative watersolubility/insolubility of the composition as well as the rate ofprecipitation of the copolymer in an aqueous solution. In a particularlypreferred embodiment, the copolymers employed herein comprise a molepercent of ethylene of from about 25 to about 60 and a mole percent ofvinyl alcohol of from about 40 to about 75, more preferably a molepercent of ethylene of from about 40 to about 60 and a mole percent ofvinyl alcohol of from about 40 to about 60.

[0029] The term “contrast agent” refers to a biocompatible (non-toxic)radiopaque material capable of being monitored during injection into amammalian subject by, for example, radiography. The contrast agent canbe either water soluble or water insoluble. Examples of water solublecontrast agents include metrizamide, iopamidol, iothalamate sodium,iodomide sodium, and meglumine. The term “water insoluble contrastagent” refers to contrast agents which are insoluble in water (i.e., hasa water solubility of less than 0.01 milligrams per milliliter at 20°C.) and include tantalum, tantalum oxide and barium sulfate, each ofwhich is commercially available in the proper form for in vivo use andpreferably having a particle size of 10 μm or less. Other waterinsoluble contrast agents include gold, tungsten and platinum powders.Methods for preparing such water insoluble biocompatible contrast agentshaving an average particle size of about 10 μm or less are describedbelow. Preferably, the contrast agent is water insoluble (i.e., has awater solubility of less than 0.01 mg/ml at 20° C.)

[0030] The term “biocompatible solvent” refers to an organic materialliquid at least at body temperature of the mammal in which thebiocompatible polymer is soluble and, in the amounts used, issubstantially non-toxic. Suitable biocompatible solvents include, by wayof example, dimethylsulfoxide, analogues/homologues ofdimethylsulfoxide, ethanol, ethyl lactate, acetone, and the like.Aqueous mixtures with the biocompatible solvent can also be employedprovided that the amount of water employed is sufficiently small thatthe dissolved polymer precipitates upon injection into a human body.Preferably, the biocompatible solvent is ethyl lactate ordimethylsulfoxide.

[0031] The term “encapsulation” as used relative to the contrast agentbeing encapsulated in the precipitate is not meant to infer any physicalentrapment of the contrast agent within the precipitate much as acapsule encapsulates a medicament. Rather, this term is used to meanthat an integral coherent precipitate forms which does not separate intoindividual components, for example into a copolymer component and acontrast agent component.

[0032] The compositions employed in the methods of this invention areprepared by conventional methods whereby each of the components is addedand the resulting composition mixed together until the overallcomposition is substantially homogeneous. For example, sufficientamounts of the selected polymer are added to the biocompatible solventto achieve the effective concentration for the complete composition.Preferably, the composition will comprise from about 2.5 to about 20.0weight percent of the polymer based on the total weight of thecomposition and more preferably from about 4 to about 12 weight percent.If necessary, gentle heating and stirring can be used to effectdissolution of the polymer into the biocompatible solvent, e.g., 12hours at 50° C.

[0033] Sufficient amounts of the contrast agent are then optionallyadded to the biocompatible solvent to achieve the effectiveconcentration for the complete composition. Preferably, the compositionwill comprise from about 10 to about 40 weight percent of the contrastagent and more preferably from about 20 to about 40 weight percent andeven more preferably about 30 to about 35 weight percent. When thecontrast agent is not soluble in the biocompatible solvent, stirring isemployed to effect homogeneity of the resulting suspension. In order toenhance formation of the suspension, the particle size of the contrastagent is preferably maintained at about 10 μm or less and morepreferably at from about 1 to about 5 μm (e.g., an average size of about2 μm). In one preferred embodiment, the appropriate particle size of thecontrast agent is prepared, for example, by fractionation. In such anembodiment, a water insoluble contrast agent such as tantalum having anaverage particle size of less than about 20 microns is added to anorganic liquid such as ethanol (absolute) preferably in a cleanenvironment. Agitation of the resulting suspension followed by settlingfor approximately 40 seconds permits the larger particles to settlefaster. Removal of the upper portion of the organic liquid followed byseparation of the liquid from the particles results in a reduction ofthe particle size which is confirmed under an optical microscope. Theprocess is optionally repeated until a desired average particle size isreached.

[0034] The particular order of addition of components to thebiocompatible solvent is not critical and stirring of the resultingsuspension is conducted as necessary to achieve homogeneity of thecomposition. Preferably, mixing/stirring of the composition is conductedunder an anhydrous atmosphere at ambient pressure. The resultingcomposition is heat sterilized and then stored preferably in sealedamber bottles or vials until needed.

[0035] Each of the polymers recited herein is commercially available butcan also be prepared by methods well known in the art. For example,polymers are typically prepared by conventional techniques such asradical, thermal, UV, gamma irradiation, or electron beam inducedpolymerization employing, as necessary, a polymerization catalyst orpolymerization initiator to provide for the polymer composition. Thespecific manner of polymerization is not critical and the polymerizationtechniques employed do not form a part of this invention. In order tomaintain solubility in the biocompatible solvent, the polymers describedherein are preferably not cross-linked.

[0036] In another particularly preferred embodiment of theimplant-forming or augmenting solution, the biocompatible polymercomposition can be replaced with a biocompatible prepolymer compositioncontaining a biocompatible prepolymer. In this embodiment, thecomposition comprises a biocompatible prepolymer, an optionalbiocompatible water insoluble contrast agent preferably having anaverage particle size of about 10 μm less and, optionally, abiocompatible solvent.

[0037] The term “biocompatible prepolymer” refers to materials whichpolymerize in situ to form a polymer and which, in the amounts employed,are non-toxic, chemically inert, and substantially non-immunogenic whenused internally in the patient and which are substantially insoluble inphysiologic liquids. Such a composition is introduced into the body as amixture of reactive chemicals and thereafter forms a biocompatiblepolymer within the body. Suitable biocompatible prepolymers include, byway of example, cyanoacrylates, hydroxyethyl methacrylate, siliconprepolymers, and the like. The prepolymer can either be a monomer or areactive oligomer. Preferably, the biocompatible prepolymer is alsonon-inflammatory when employed in situ.

[0038] Prepolymer compositions can be prepared by adding sufficientamounts of the optional contrast agent to the solution (e.g., liquidprepolymer) to achieve the effective concentration for the completepolymer composition. Preferably, the prepolymer composition willcomprise from about 10 to about 40 weight percent of the contrast agentand more preferably from about 20 to about 40 weight percent and evenmore preferably about 30 weight percent. When the contrast agent is notsoluble in the biocompatible prepolymer composition, stirring isemployed to effect homogeneity of the resulting suspension. In order toenhance formation of the suspension, the particle size of the contrastagent is preferably maintained at about 10 μm or less and morepreferably at from about 1 to about 5 μm (e.g., an average size of about2 μm).

[0039] When the prepolymer is liquid (as in the case of polyurethanes),the use of a biocompatible solvent is not absolutely necessary but maybe preferred to provide for an appropriate viscosity in theimplant-forming solution. Preferably, when employed, the biocompatiblesolvent will comprise from about 10 to about 50 weight percent of thebiocompatible prepolymer composition based on the total weight of theprepolymer composition. When a biocompatible solvent is employed, theprepolymeric composition typically comprises from about 90 to about 50weight percent of the prepolymer based on the total weight of thecomposition.

[0040] In a particularly preferred embodiment, the prepolymer iscyanoacrylate which is preferably employed in the absence of abiocompatible solvent. When so employed, the cyanoacrylate adhesive isselected to have a viscosity of from about 5 to about 20 centipoise at20° C.

[0041] The particular order of addition of components is not criticaland stirring of the resulting suspension is conducted as necessary toachieve homogeneity of the composition. Preferably, mixing/stirring ofthe composition is conducted under an anhydrous atmosphere at ambientpressure. The resulting composition is sterilized and then storedpreferably in sealed amber bottles or vials until needed.

[0042] Other suitable implant-forming materials for introduction intoone or both of muscle layers 201 and 202 include injectable bioglass asdescribed in Walker et al., “Injectable Bioglass as a PotentialSubstitute for Injectable Polytetrafluorethylene Particles”, J. Urol.,148:645-7, 1992, small particle species such as polytetrafluoroethylene(PTFE) particles in glycerine such as Polytef®, biocompatiblecompositions comprising discrete, polymeric and silicone rubber bodiessuch as described in U.S. Pat. Nos. 5,007,940, 5,158,573 and 5,116,387to Berg, biocompatible compositions comprising carbon coated beads suchas disclosed in U.S. Pat. No. 5,451,406 to Lawin, collagen and otherbiodegradable material of the type disclosed in U.S. Pat. No. 4,803,075to Wallace et al. and other known injectable materials.

[0043] Specific embodiments of implant-forming solutions suitable foruse in the apparatus and methods of the invention are described in U.S.Pat. Nos. 5,667,767 dated Sep. 16, 1997, U.S. Pat. No. 5,580,568 datedDec. 3, 1996 and U.S. Pat. No. 5,695,480 dated Dec. 9, 1997 andInternational Publication Number WO 97/45131 having an InternationalPublication Date of Dec. 4, 1997, the entire contents of which areincorporated herein by this reference.

[0044] A suitable supply assembly for depositing one or more implants inthe rectal area of the patient is coupled to the proximal extremity ofthe probe member. The supply assembly includes at least a firstreservoir containing the implant-forming material. As noted above, suchimplant-forming solution preferably includes at least one nonaqueoussolution and more preferably is a solution of a biocompatible polymerand a biocompatible solvent. Preferably, the supply assembly furtherincludes a second reservoir containing a solvent and preferably abiocompatible solvent such as dimethyl sulfoxide (DMSO) and a thirdreservoir containing a suitable aqueous or physiologic solution such assaline.

[0045] In the method of the present invention, let it be assumed that inpreparing for the procedure, the gastrointestinal tract of a patient hasbeen previously evaluated by using any or all techniques and proceduresavailable in the art including, but not limited to, upper and lowergastrointestinal radiographic studies, motility studies, endoscopy withbiopsies, proctoscopy, sigmoidoscopy and colonoscopy. Assuming that thepatient's pretreatment evaluation warrants the procedure hereinafterdescribed and that the patient has received a typical surgical bowelpreparation as is known in the art, the patient can be brought into anoutpatient clinic or an operating room in a hospital. The patient ispreferably placed in either a lithotomy or jackknife position on anoperating or examining table or on a gurney.

[0046] After intravenous access has been accomplished and the patienthas been appropriately sedated or anesthetized, the physician inserts asuitable probe member or scope, for example an anoscope, aproctoscope ora sigmoidoscope, in a standard manner. After appropriate positioning ofthe scope to identify the appropriate region of the rectal wall 24 fortreatment, the scope is removed from the rectum. The physician or hisassistant then fills and primes syringe 41, in the manner described inU.S. patent application Ser. No. 09/286,245 filed Apr. 5,1999, with asaline or other suitable aqueous or physiological solution from thethird reservoir of the supply assembly, referred to herein as the salinesolution. The distal extremity of needle 43 is introduced through anus23 of the patient and passed into the region of anal sphincter 31 asseen in FIG. 1. In this regard, the handle of syringe 41 is grasped bythe physician in order to introduce the distal extremity of needle 43into anus 23 and advance it in a cephalad direction to the vicinity ofsphincter 31, the area to be treated. By subsequently advancing needle43 laterally, the physician penetrates wall 24 of anus 23 with thesharpened end of needle 43 which causes the distal end thereof topenetrate anal sphincter 31.

[0047] Alternatively, the scope can be maintained in anal canal 23during the procedure in order to maximize exposure and visibility. Insuch a case, needle 43 or a catheter-type needle, that is a needle atthe end of a catheter, is advanced through the scope and beyond thedistal end thereof to the area of treatment instead of being advanceddirectly through anus 23. It should also be appreciated that thetreatment of the present invention can be performed with anappropriately modified biopsy guide in conjunction with a trans-rectalultrasound system (TRUS).

[0048] In one of the embodiments of the invention the saline solutionfrom the third reservoir of the supply assembly can be injected intowall 24 and more specifically into internal sphincter 32. The salineinjection creates to a local edema for facilitating acceptance of theimplant by the body of the patient. The amount of injected salinesolution can range from 0.25 to 10 cc and preferably ranges from 1 to 3cc. Thereafter, the physician retracts needle 43 from wall 24, removessyringe 41 from anus 23, subsequently withdrawing the remaining salinesolution from the needle passage and flushing the needle passage withDMSO from the second reservoir to ensure that the saline solution hasbeen removed from the passage. Removal of the saline solution from theneedle passage and the cleansing of the passage with DMSO inhibitspremature precipitation within syringe of the biocompatible polymer inthe implant-forming solution of the first reservoir from the DMSO insuch implant-forming solution. The needle passage is next primed withthe implanting-forming solution from the first reservoir.

[0049] The physician subsequently causes the distal portion of needle 43to penetrate the internal sphincter and thereafter causes a preselectedamount of the implant-forming solution to be introduced through needle43. The optional contrast agent within the implant-forming solutionpermits the viewing of the solution by means of fluoroscopy. Inaddition, the introduction of the implant-forming solution into wall 24can be monitored by standard abdominal or pelvic ultrasound or,preferably, by high resolution trans-rectal ultrasound system. The rateof injection of the implant-forming solution into the space can rangefrom 0.1 cc per minute to 10 cc per minute. Once the implant-formingsolution has been introduced into wall 24, the biocompatible polymer ofthe implant-forming solution precipitates to form one or more discretedeposits or solid implants 51 (see FIGS.1-2). The bio-compatible solventdisperses in body 22. The amount of implant-forming solution injectedinto wall 24 for each implant 51 can range from 0.05 cc to 10 cc.

[0050] It has been found that an injection of a suitable aqueous orphysiologic solution such as a saline solution into wall 24 prior to theinjection of the implant-forming solution serves to condition or preparethe tissue in wall 24, that is to help wall 24 receive theimplant-forming solution and thus facilitate implantation of thebiocompatible polymer. Although the conditioning solution has beendescribed as a saline solution, antibiotics and/or anti-inflammatoriescan be introduced locally to condition the tissue. The use of a salinesolution as discussed above also facilitates the rapid dispersion of theDMSO from the implant-forming solution thus diluting any local irritanteffect of the DMSO. The saline solution further acts as a heat sink forthe heat of dissolution of the solvent.

[0051] Any number and configuration of implants 51 can be formed inrectal wall 24. In one preferred method, a plurality ofcircumferentially spaced-apart implants 51 are formed in rectal wall 24(see FIGS. 1-2). The discrete implants 51 can be formed in submucosallayer 27, circular muscle layer 28 and/or longitudinal muscle layer 29.In addition, the implants 51 can be formed in anal sphincter 31, asshown in FIGS. 1-2 where implants 51 are located in sphincter aniinternus 32. It should be appreciated that implants 51 can also beformed in any or all of the portions of sphincter ani internus 32,sphincter ani externus 33, namely, deep external sphincter 34,superficial external sphincter 36 and/or subcutaneous external sphincter37, and/or in the intersphincteric space 39. An exemplary implant 52formed by dashed lines is shown in each of deep external sphincter 34,superficial external sphincter 36 and subcutaneous external sphincter 37in FIG. 1.

[0052] When a plurality of implants 51 are formed in rectal wall 24 inthe vicinity of anus 23, such implants can be disposed substantially ina plane, as shown in FIGS. 1-2, in multiple planes or out of plane.Implants 51 can be symmetrically or asymmetrically disposed around anus23. Such implants can be formed from pulsed or continuous injections ofa solution from syringe 41 or by any other suitable manual or automatedmeans.

[0053] In a particularly preferred embodiment of the present inventionone or more elongate implants 53 having respective longitudinal axes 54are formed in lax internal sphincter 32, as seen in FIG. 3, by using anyof the solutions hereinbefore described. In order to perform the methodin such a manner, the physician utilizes a longer needle 43, preferablya needle having a length of at least 3.5 to 5.0 inches, under directvision. Holding syringe 41 as hereinbefore described, the physicianadvances needle 43 similarly, in a cephalad and then lateral directioninto and through internal sphincter 32 until the distal end of needle 43abuts or approximates anorectal border 38, above internal sphincter 32.Using a pull-back technique of injection, the physician injects anddeposits implant-forming solution in the muscle of internal sphincter 32while slowly withdrawing needle 43, thereby creating an elongate,longitudinally oriented implant 53 therein. Preferably, rod-shapedimplants 53 formed in this manner have a length of approximately 20-100millimeters and a width of approximately 0.1 to 25 millimeters,depending on the dimensions of the sphincter being augmented or treated.

[0054] Elongate implants 53 preferably extend from the cephalad tocaudal ends of internal sphincter 32 or from anorectal border 38 toopening of anus 23. As such, the longitudinal axis of 54 each of theimplants 53 extends substantially parallel to the centerline of therectum. It should be appreciated that with this technique, while asingle elongate implant 53 can be deposited at any location withininternal sphincter 32, a greater number of implants can be spaced aparttherein. Preferably, at least four such implants are placedcircumferentially, at approximately ninety degrees of separation fromone another, within internal anal sphincter 32. Each quadrant ofinternal sphincter 32 is thereby enlisted to participate substantiallyequally in augmenting sphincter competency. In this manner elongateimplants 53 bolster, stiffen and increase the tonus of an otherwise laxinternal sphincter 32, helping to maintain and restore the anatomicalconfiguration and function thereof. As hereinbefore described,diminished distensibility of internal sphincter 32 ameliorates analincontinence.

[0055] In another preferred embodiment, similar rod-like implants 53 areformed within a disrupted internal sphincter 32 in order to restore thestructural and functional integrity thereof as seen in FIG. 4. Theapparatus and technique of forming implants 53 are as hereinbeforedescribed. Any of the materials discussed above for creating implants ina body can be utilized. However, the implants are preferably formed froman injectable solution of a biocompatible polymer and a biocompatiblesolvent from which the biocompatible polymer precipitates when thesolution is introduced into the body. Inasmuch as the size anddistribution of an implant created depends in part upon the quantity ofimplant-forming material, speed of injection thereof and the space ortissue into which the material is injected, the technique of pull-backinjection utilized with this embodiment is performed particularly slowlyin order to form an elongate implant 53 which bridges the damaged orincompetent portion 60 of internal sphincter 32. Specifically, needle 43is extended up through the second end portion 59, the damaged portion 60and then the first end 58, before being slowly pulled back duringdelivery of the implant-forming material into the sphincter 32. Bybracing the damaged internal sphincter 32, function is restored and endportions 58 and 59 can again properly function together as a unit.

[0056] The elongate implants of the present invention can be formed inany other portion of the wall of the gastrointestinal tract, or in anyother wall forming a passageway in a body of a mammal. In addition, thetechnique disclosed above for bracing or restoring a muscle, for examplea muscle having a damaged or incompetent portion, can be utilizedelsewhere in a body of a mammal. It should further be appreciated thatarc-shaped, arcuate and/or ring-shaped implants, for example of the typedisclosed in U.S. patent application Ser. No. 09/447,663 filed Nov. 23,1999, the entire content of which can be incorporated herein by thisreference, can also be formed in any of the muscle layers of the rectalwall 24.

[0057] In another particularly preferred embodiment of the presentinvention, one or more implants 55 are formed in intersphincteric space39, as seen in FIGS. 5-6, either exclusively or in conjunction withinternal sphincter implants 51 hereinbefore described. Techniques andapparatus are as hereinbefore described. The implants are preferablyformed from an injectable solution of a biocompatible polymer and abiocompatible solvent from which the biocompatible polymer precipitateswhen the solution is introduced into the body. In addition,intersphincteric space 39 is located using pelvic ultrasound or,preferably, high resolution trans-rectal ultrasound. Preferably,intersphincteric implants 55 are circumferentially spaced apart andarcuate or ring-like in configuration. In comparison to external orinternal sphincters 33 and 32, intersphincteric space 39 issubstantially without striations, septa or fibrous bands and, as such,is more capacious. Therefore, a fully circumferential ring-like implantcan be much more easily formed therein, for example by ejecting materiallaterally or horizontally out of side openings of needle 43. Acircumferential intersphincteric implant 55 facilitates augmentation ofa lax anal sphincter 31. To this end, preferably, the physician uses aneedle 43 provided with a plurality of longitudinally and spaced-apartopenings. In order to create a plurality of implants, multiple separateinjections in intersphincteric space 39 are performed. Two arcuateimplants are shown in FIGS. 5 and 6. A ring-shaped implant can be formedby forming a plurality of arcuate implants which abut each other to formthe ring-shaped implant.

[0058] The optional contrast agent in the implants permits the implantsto be monitored after completion of the procedure described above. Thusthe stability of the implants and their configurations can be observedover time. Further procedures can be performed to supplement previouslyformed implants. It should be appreciated that the implants of thepresent invention can be used as delivery vehicles for other materialssuch as radio-isotopes, chemotherapeutic agents, anti-inflammatoryagents and/or antibiotics.

[0059] The treatment of the invention can be reversed by expanding theaugmented or coapted region created by the implants in an suitablemanner such as by use of a balloon or bougie.

[0060] Although the method of the invention has been described asincluding the injection of a saline solution into the wall 24 prior toan injection of implant-forming solution into the wall 24, it should beappreciated that the implant-forming solution can be injected into wall24 without such a prior injection of saline or other solution. A salineor other aqueous or physiologic solution can optionally be introducedinto the wall 24 after the introduction of the implant-forming solutiontherein to facilitate dispersion of the DMSO or other biocompatiblesolvent present in the implant forming solution. It can thus be seenthat the invention is broad enough to cover the introduction of anyconditioning solution into the tissue after the treatment to facilitatethe treatment.

[0061] Although in the described method of the invention the deliveryneedle has been introduced through the rectal wall, formation orplacement of implants in or about the anal sphincter can be accomplishedtransperineally and be within the scope of the present invention. Inthis regard, one or more needles for delivery of the implant-formingmaterial can be introduced through the perineum for accessing the analsphincter, the intersphincteric space 39 and/or other tissue in thevicinity thereof. Such implant formation can be visualized and monitoredunder ultrasound or any other conventional means. As such, introductioninto the rectal wall can be accomplished from the rectal cavity orthrough the perineum.

[0062] It should be appreciated that additional configurations and typesof needles are included within the purview of the present invention.Thus, needles provided with any combination of longitudinally and/orcircumferentially spaced-apart side openings can be used to facilitatethe formation of arcuate, thicker and/or wider implants. In addition toneedles carrying cutting tips, needles provided with blunt tips may beutilized.

[0063] It should also be appreciated that other apparatus can beutilized to augment, bulk or otherwise decrease the distensibility ofrectal wall 24 in the vicinity of anus 23. For example, as shown in FIG.7, a delivery mechanism or gun 56 which provides preselected amounts ofthe solution into rectal wall 24 can be utilized. Gun 56 issubstantially similar to the gun shown in U.S. patent application No.Ser. No. 09/286,245 filed Apr. 5, 1999. Syringe 41 can be utilized withgun 56 and a stop cock 57 can be disposed between syringe 41 and needle43 for permitting a biocompatible solvent such as DMSO and/or an aqueoussolution such as saline to be alternatively introduced through needle 43into rectal wall 24. Reservoirs such as additional syringes (not shown)can be utilized in this regard.

[0064] It can be seen from the foregoing that the implants formed by themethod of the present invention can be of a variety of sizes and formedin a variety of configurations in the wall of the rectum and anal canal.Any material or solution utilized for forming such implants can beinjected into the wall in a variety of manual or automated and pulsed oncontinuous manners. One or more implants can be formed in any of thelayers of the wall, including any of the muscle layers or inter-muscularlayers of the wall. Without limiting the foregoing, it should beappreciated that any of the implants of the invention hereinbeforedescribed can be formed in any sphincter-like muscle or mechanism in thegastrointestinal tract or elsewhere in the body.

What is claimed is:
 1. A method for treating fecal incontinence in abody of a mammal having a rectum formed by a rectal wall extending to ananus wherein the rectal wall includes a sphincter muscle surrounding theanus comprising the steps of introducing at least one nonaqueoussolution into the rectal wall in the vicinity of the anus and formingfrom the at least one nonaqueous solution a nonbiodegradable solid inthe rectal wall.
 2. The method of claim 1 wherein the forming stepincludes the step of forming a plurality of discrete nonbiodegradablesolids in the rectal wall around the anus.
 3. The method of claim 2wherein said forming step includes forming a plurality of rod-shapedsolids.
 4. The method of claim 1 wherein the rectal wall includes anintersphincteric space and wherein the forming step includes the step offorming said solid in the intersphincteric space.
 5. The method of claim1 wherein the rectal wall includes an anorectal border and wherein theforming step includes forming at least one solid extending from theanorectal border to the anus.
 6. The method of claim 1 wherein the solidis elongate in shape.
 7. The method of claim 1 wherein the solid isarcuate in shape.
 8. The method of claim 7 wherein the solid isring-shaped.
 9. The method of claim 1 wherein the introducing stepincludes the step of introducing the at least one nonaqueous solutioninto the sphincter muscle.
 10. The method of claim 9 wherein thesphincter muscle includes a sphincter ani internus and wherein theintroducing step includes the step of introducing the at least onenonaqueous solution into the sphincter ani internus.
 11. The method ofclaim 10 wherein the solid is elongate in shape.
 12. The method of claim9, the sphincter muscle including a sphincter ani externus, wherein theintroducing step includes the step of introducing the at least onenonaqueous solution into the sphincter ani externus.
 13. The method ofclaim 1 wherein the at least one solution is a solution of abiocompatible polymer and a biocompatible solvent and wherein theforming step includes the step of precipitating the biocompatiblepolymer from the solution so that the biocompatible polymer solidifiesin the rectal wall in the vicinity of the anus and the biocompatiblesolvent disperses in the body.
 14. The method of claim 13 wherein theintroducing step includes the steps of extending a needle into therectal wall and supplying the biocompatible polymer and thebiocompatible solvent through the needle into the rectal wall.
 15. Themethod of claim 14 wherein the extending step includes the step ofextending the needle from the rectal cavity into the rectal wall. 16.The method of claim 14 wherein the extending step includes the step ofextending the needle through the perineum into the rectal wall.
 17. Amethod for treating fecal incontinence in a body having an analsphincter comprising the step of forming at least one nonbiodegradableimplant in said sphincter.
 18. The method of claim 17 further includingthe step of introducing at least one solution into said sphincter andforming said implant from the at least one solution.
 19. The method ofclaim 18 wherein the introducing step includes the steps of introducinga needle into the sphincter and introducing said at least one solutionthrough the needle into the sphincter.
 20. The method of claim 17wherein said sphincter has a damaged portion, further including the stepof bridging the damaged portion with the implant.
 21. The method ofclaim 17 wherein the anal sphincter has an internal sphincter andwherein the forming step includes the step of forming the at least oneimplant in said internal sphincter.
 22. A method for treating fecalincontinence in a body of a mammal having a rectum formed by a rectalwall comprising the step of forming a rod-like implant in the rectalwall.
 23. The method of claim 22 wherein the rectum has a centerline andthe rod-like implant has an axis extending substantially parallel to thecenterline of the rectum.
 24. The method of claim 23 wherein the formingstep includes the step of introducing at least one nonaqueous solutioninto the rectal wall.
 25. The method of claim 24 wherein the at leastone nonaqueous solution is a solution of a biocompatible polymer and abiocompatible solvent and the forming step includes the step ofprecipitating the biocompatible polymer from the solution so that thebiocompatible polymer solidifies in the rectal wall in the vicinity ofthe anus and the biocompatible solvent disperses in the body.